In addition, and given the fact that such floors are often subjected to high loads, further load transfer elements are typically included in the aforementioned joint profiles to assure that the vertical load on one floor panel is transmitted to the adjacent floor panel in an optimal way and thereby preventing a vertical tilting of the floor panels with respect to each other. However, when driving over such an expansion joint with heavily loaded vehicles such as forklifts, which often have particularly hard Vulkollan wheels, the presence of such load transfer elements cannot prevent damage of the upper circumferential edges of the slabs or to the wheels, due to the undesirable shock of the vehicle when passing the groove-like gap between the floor elements. This is especially due to the fact that the joint profile making up the edges of the floor elements is made of steel and therefore much harder than the commonly soft outer circumference surface of the wheels.
In an effort to address the drawback of the groove-like gap in the existing joint profiles, alternatives have been presented wherein the edges of the floor members by means of coggings interlock with one another. See for example AT113488, JP2-296903, DE3533077 or WO2007144008. However, in as far each of said arrangements ensures that the wheels when leaving one edge are already supported on the boundary of the other; the mere presence of such cogging interlocks is insufficient to prevent damage at the upper circumferential edges of the floor elements. Vertical tilting of the floor members may still result in differences in height between the plates which gives rise to edges, further shocks and eventual damages to the floor. Consequently, also in these interlocking joint profiles load transfer elements will be required to assure that the vertical load on one floor panel is transmitted to the adjacent floor panel in an optimal way and thereby preventing a vertical tilting of the floor panels.
Such load transfer elements come in different shapes and embodiments, such as for example wedge-shaped dowels (DE 102007020816); horizontal grooves and protrusions cooperating with one another (BE1015453, BE1016147); plate dowels (U.S. Pat. No. 5,674,028, EP1584746, US2008222984) or bar dowels (EP0410079, U.S. Pat. No. 6,502,359, WO03069067, EP0609783). Irrespective of their embodiment, said load transfer elements needs to be incorporated in the floor deck adding not only to a minimum thickness for the floor, but also to additional material to be used and to complexity in construction.
In addition, metal interlocking end plates such as shown in AT113488 and JP-2-29603, still result in an abrupt change of expansion coefficient at the boundary of the floor slabs. As a consequence, these end plates tend to loosen over time with floor damage at the boundary between the concrete floor slabs at the metal end plates.